A former safety director at a Michigan hyperbaric facility has been sentenced to prison following the death of a five-year-old boy in a chamber fire, after prosecutors said established fire-safety procedures had been disregarded.
A Sechrist monoplace hyperbaric oxygen chamber. The photograph is illustrative and does not show the chamber involved in the Oxford Center fire in Michigan.
Jeffrey Mosteller, former safety director at the Oxford Center in Troy, Michigan, has been sentenced to 19 months to 15 years in prison after pleading no contest to involuntary manslaughter over the death of five-year-old Thomas Cooper.
Cooper died on 31 January 2025 when a monoplace hyperbaric oxygen chamber caught fire while he was undergoing treatment. His mother was injured while attempting to rescue him.
Safety protocols disregarded
The case centred on safety precautions intended to prevent fire in the oxygen-rich environment of a hyperbaric chamber.
According to the Michigan Attorney General's office, both the National Fire Protection Association and Sechrist, the chamber manufacturer, had established safety protocols for its operation. Prosecutors said Mosteller deliberately disregarded those protocols and precautions.
At sentencing, Oakland County Circuit Court Judge Kwamé Rowe criticised Mosteller for acting as though he knew better than the national fire code, the manufacturer's manual and his own training and experience.
The case has particular relevance to the wider hyperbaric community because elevated concentrations of oxygen greatly increase the consequences of an ignition source. Proper grounding, compatible clothing and materials, equipment maintenance and staff training are among the precautions used to reduce that risk.
FDA warned facilities about fire risk
The fatality was followed in August 2025 by a US Food and Drug Administration safety communication concerning hyperbaric oxygen therapy devices. The FDA said it was aware of reports of fires resulting in serious injuries and deaths, although it did not attribute those incidents to a common cause.
Its recommendations include following manufacturers' instructions, ensuring fire-prevention measures are observed, using proper grounding equipment, maintaining staff training and keeping potentially prohibited electrical or static-producing items out of chambers. The agency also warns that synthetic fabrics can generate more static electricity than some other materials.
Three defendants still face proceedings
Mosteller is the first of four people charged in connection with Cooper's death to be sentenced.
Oxford Center owner Tamela Peterson and manager Gary Marken were ordered to stand trial on second-degree murder charges, or alternatively involuntary manslaughter. Chamber operator Aleta Moffitt faces involuntary manslaughter and a charge relating to allegedly placing false information in medical records. Those proceedings remain pending, and the defendants are presumed innocent unless proven guilty.
Michigan Attorney General Dana Nessel has described Cooper's death as a preventable tragedy resulting from the failure to follow established safety standards.
